CN217387086U

CN217387086U - Air inlet structure

Info

Publication number: CN217387086U
Application number: CN202122813186.0U
Authority: CN
Inventors: 林佳继; 祁文杰; 梁笑; 范伟; 毛文龙; 卢佳
Original assignee: Shenzhen Laplace Energy Technology Co Ltd
Current assignee: Laplace New Energy Technology Co ltd
Priority date: 2021-11-17
Filing date: 2021-11-17
Publication date: 2022-09-06
Anticipated expiration: 2031-11-17

Abstract

The utility model discloses an air inlet structure, including even stream device, even stream device adopts tubbiness structure, including the staving, staving one end opening, the closed surface is connected to the staving other end, is equipped with the trompil on the closed surface. The utility model discloses in, the setting of staving can be concentrated the gas that gets into even flow device, avoids gaseous diffusion to all around. The gas flows out from the open holes on the closed surface and is uniformly scattered, so that the direct impact of the gas flow on the silicon wafer is avoided, the uniformity among diffusion sheets can be improved, and the square resistance among the sheets is reduced.

Description

Air inlet structure

Technical Field

The invention relates to the field of solar N-type and P-type cell manufacturing, in particular to an air inlet structure.

Background

The energy is put and benefited as three major pillars for social development, not only is the power for the proceeding and development of human production activities, but also plays a great role in promoting the development of human socioeconomic development. For decades, countries around the world have been actively exploiting fossil fuels for their own developments. However, the excessive use of fossil fuel causes serious pollution to air, and becomes a great problem in the whole world. In order to cope with the influence of the traditional fossil energy on the environment, the consumption proportion of the traditional fossil energy needs to be reduced, and green energy sources such as solar energy, wind energy, biological energy and the like need to be developed. Among them, solar energy is an ideal renewable energy, and meets the requirements of environmental protection and sustainable development, and thus has received wide attention from various countries.

At present, the process of manufacturing monocrystalline silicon solar cells in large scale generally comprises the following steps: texturing, boron diffusion, etching, phosphorus diffusion, PSG/BSG removal, antireflection film plating, electrode printing and sintering. The PN junction manufactured by diffusion is the heart of the solar cell, and determines parameters such as junction depth, surface impurity concentration and the like of the PN junction of the solar cell. The non-uniformity of diffusion directly affects the normal distribution of cell electrical performance parameters, resulting in an increase in the fraction of cell inefficiency. For a cell with an emission-high sheet resistance diffusion process, the influence on the cell performance will be more serious.

Disclosure of Invention

To the above-mentioned condition, for overcoming prior art's defect, the utility model provides an air inlet structure can improve diffusion piece within a definite time homogeneity, reduces between the piece that the square resistance is extremely poor.

In order to achieve the above object, the present invention provides the following technical solutions:

the air inlet structure comprises a flow equalizing device, wherein the flow equalizing device is of a barrel-shaped structure and comprises a barrel body, one end of the barrel body is open, the other end of the barrel body is connected with a closed surface, and an opening is formed in the closed surface.

Furthermore, the lower part of the uniform flow device is provided with a supporting piece which is fixedly connected with the barrel body.

Further, the support is cylindrical.

Further, the support member is hollow inside.

Further, the support member is open at one end.

Further, the flow homogenizing device also comprises a connecting piece, and the connecting piece is connected with the supporting piece.

Further, the connector is located at the side of the tub opening.

Further, the gas inlet structure further comprises a gas supplementing pipe configured to be used for supplementing gas, wherein the gas can be nitrogen or/and inert gas.

Furthermore, the air supply pipe is in a plug form, one end of the air supply pipe is closed, the other end of the air supply pipe is open and used for introducing air, and an air outlet is formed in the air supply pipe.

Furthermore, the air supply pipe is inserted into the furnace tube from the furnace tail and extends to the furnace mouth; the end of the air supply pipe close to the furnace mouth is closed, and the other end is opened.

The utility model has the advantages that:

(1) in the utility model, the air inlet structure comprises a flow equalizing device which adopts a barrel-shaped structure and comprises a barrel body, the other end of the barrel body is connected with a closed surface (namely the other end is closed), and the closed surface is provided with a hole; the arrangement of the barrel body can centralize the gas entering the uniform flow device, and the gas is prevented from diffusing around. The gas flows out from the open hole on the closed surface and is uniformly scattered, so that the gas flow is prevented from directly impacting the silicon wafer, and the inter-wafer difference of the square resistances of the upper, middle and lower silicon wafers at the furnace tail can be improved.

(2) The utility model discloses in, the sealing surface is not the whole face all to be equipped with the trompil, and the shape and the little boat shape of trompil region correspond (can set up according to the shape of little boat), are favorable to gaseous more concentrated going to little boat rather than flowing away from little boat limit. The barrel-shaped uniform flow device has better stability in the furnace tube, can not shake, is additionally provided with the connecting piece, and is convenient to put in and take out the furnace tube.

(3) The utility model discloses in, the shape of connecting piece is similar to the arch handle, and two cylindrical support piece's one end is connected respectively at the both ends of connecting piece, and connecting piece person of facilitating the use gripping is favorable to taking or placing even flow device in to the boiler tube, and simultaneously, the connecting piece is located this one side of staving opening, can balance the weight distribution of whole device for overall structure is comparatively stable.

(4) The utility model discloses in, the inlet structure still includes the air supplement pipe, can be used for supplementing nitrogen gas, can improve the homogeneity between extraction opening position piece under the structure of not changing current bleeding, and almost does not have the influence to the square resistance in other boats, can realize the regional square resistance of independently adjusting space. The utility model discloses an improvement to homogeneity between burner plate can be so that productivity and homogeneity all obtain promoting, need not increase boiler tube length, have saved board space and board manufacturing cost. The uniformity of the sheet resistance after diffusion is better, which is beneficial to the matching of the subsequent process, and the overall electrical property is more stable.

Drawings

FIG. 1 is a schematic view of the structure of a flow uniformizing apparatus.

Figure 2 is a schematic view of the structure of the flow-homogenizing device from another perspective (showing the structure of the connecting piece).

FIG. 3 is a schematic view of a uniform flow device installed inside a furnace tube.

FIG. 4 is a schematic structural view of the gas supply pipe inside the furnace tube (other parts in the furnace tube are hidden).

FIG. 5 is a cross-sectional view of the furnace tube without the addition of a supplemental gas tube (showing the change in gas flow).

FIG. 6 is a cross-sectional view of the furnace tube with the addition of an air supplement tube (showing the change in gas flow).

Detailed Description

The following detailed description is provided to further explain the technical solutions of the present invention with reference to the accompanying drawings, and it should be noted that the detailed description is only for the details of the present invention and should not be considered as a limitation of the present invention.

Example 1

As shown in fig. 1-2, an air inlet structure includes a flow equalizing device, the flow equalizing device is a barrel structure and includes a barrel body 1a, one end of the barrel body 1a is open (here, a first opening 7a), the other end of the barrel body 1a is connected to a sealing surface (i.e., the other end of the barrel body is sealed), and an opening 3a is arranged on the sealing surface 2 a. The barrel body 1a can collect the gas entering the uniform flow device and prevent the gas from diffusing to the periphery; the gas flows out from the open hole 3a on the closed surface 2a and is uniformly scattered, so that the gas flow is prevented from directly impacting the silicon wafer.

In some preferred manners, the shape of the opening 3a may be circular, oval, square, triangular, etc., and the shape of the opening is not limited in this application. The number of the openings can also be set according to actual needs. In this embodiment, the opening is circular.

In some preferred modes, as shown in fig. 1-2, a support 4a is provided at the lower part of the flow equalizing device, the support 4a is fixedly connected with the barrel body 1a, the support 4a can support the entire flow equalizing device, and the support 4a can be used for stably placing the flow equalizing device at a certain position, for example, the flow equalizing device can be placed inside the furnace tube. In some preferred modes, the shape of the support 4a is matched with the shape of the placement area inside the furnace tube, so that the uniform flow device is favorably and stably placed inside the furnace tube.

In some preferred forms, the support member 4a is cylindrical, and the cylindrical support member 4a is fitted to the circular tube contact portion. In this embodiment, as shown in fig. 1-2, the flow evening device comprises two cylindrical support members 4 a.

In some preferred modes, as shown in fig. 1, the supporting member 4a is hollow inside, and one end of the supporting member 4a is open (here, the second opening 8a), so that the supporting member 4a can be sleeved on the corresponding fixing member 6a, as shown in fig. 1-3, the opening direction of the supporting member 4a is opposite to the opening direction of the barrel body 1a, the uniform flow device is placed inside the furnace tube, and the supporting member 4a is sleeved on the fixing member inside the furnace tube. Since the support 4a is hollow inside, the weight of the entire flow-equalizing bucket can also be reduced. Fig. 3 shows an installation manner of the uniform flow device, and the supporting piece is sleeved on the fixing piece 6a to realize the connection of the uniform flow device and the furnace tube. In other embodiments, other modes can be adopted for installation, for example, installation similar to a buckle mode is adopted, and a clamping groove is arranged in the furnace tube and can be matched with the supporting piece to realize connection of the uniform flow device and the furnace tube.

When the flow equalizing device is used, gas can firstly pass through the opening 3a of the closed surface and then flow out of the barrel body; alternatively, the gas may be passed through the barrel 1a and then discharged from the opening 3 a.

In some preferred modes, as shown in fig. 2, the flow equalizing device further comprises a connecting piece 5a, the connecting piece 5a is connected with the supporting piece 4a, the connecting piece 5a is configured to be held by a user, and the connecting piece 5a is connected with the supporting piece 4a, so that the whole structure is stable. The connecting piece 5a can be in various shapes, such as any one or combination of shapes of a square connecting piece, an arch connecting piece, a transverse connecting piece and the like.

In this embodiment, the shape of connecting piece 5a is similar to the arch handle, as shown in fig. 2, two ends of connecting piece 5a are connected with the one end of two cylindrical support piece 4a respectively, and connecting piece 5a is convenient for the user to grasp, is favorable to taking or placing the even flow device in the boiler tube, and simultaneously, connecting piece 5a is located this side of staving 1a opening, can balance the weight distribution of whole device for whole structure is comparatively stable.

In some preferred modes, the uniform flow device is arranged at the gas inlet end of the furnace tube, and the distance between the uniform flow device and the gas inlet end is 10-15cm, so that the contact area of the gas and the uniform flow barrel can be increased, and the gas flow can be better dispersed.

In some preferred modes, as shown in fig. 1, the closed surface 2a is not provided with the opening 3a on the whole surface, and the shape of the area of the opening 3a corresponds to the shape of the boat (according to the shape of the boat), so that the gas can flow to the boat more intensively rather than flowing away from the edge of the boat. The barrel-shaped uniform flow device has better stability in the furnace tube and can not shake, and the uniform flow device comprises a connecting piece 5a, so that the uniform flow device can be conveniently put into and taken out of the furnace tube.

Example 2

In some preferred manners, as shown in fig. 4, the gas inlet structure further includes a gas supplementing pipe configured to be capable of supplementing gas, which may be nitrogen or/and inert gas, in this embodiment, the gas supplementing pipe is mainly used for supplementing nitrogen.

In some preferred modes, the air supply pipe is in the form of a plug, and is inserted into the furnace tube from the furnace tail and extends to the furnace mouth; the end of the air supply pipe close to the furnace mouth is closed, the other end is opened (the third opening 9a) for introducing air, and in some preferred modes, the air supply pipe is provided with an air outlet 10 a. The gas outlet is formed in the gas supplementing pipe, the gas outlet position can be an area with lower square resistance, and the concentration of the phosphorus source or the boron source is diluted by adding local nitrogen, so that the effect of improving the square resistance is achieved.

In this embodiment, as shown in fig. 4, the gas outlet is located right above the air supplement pipe, and the gas outlet is a circular hole with a diameter of 1.5 mm.

In the present application, the shape of the gas outlet may be square, oval, etc., and the present application does not specifically limit the shape of the gas outlet.

In this embodiment, as shown in fig. 4, the gas outlets are located right above the gas inlet pipe, the gas outlets are circular holes with a diameter of 1.5mm, and the number of the gas outlets is 6, which is a combination of 3, 2, and 1. The lower part of the first boat close to the furnace mouth is provided with 3 holes, the lower part of the second boat is provided with 2 holes, the lower part of the third boat is provided with 1 hole, and the air supply pipe passes through the lower part of the uniform flow device and extends to the lower part of the furnace mouth boat.

In some preferred forms, the diameter of the inflation tube is 12 mm. In other embodiments, the diameter of the inflation tube may be other values, and may be set according to specific requirements.

In some preferred modes, in the process source supplying step, an air supplementing pipe is added, and nitrogen is introduced; in the embodiment, the nitrogen compensation flow is set to be 0.5-2L/min in the process source supplying step.

The gas inlet structure in the present application can be used for phosphorus diffusion and also for boron diffusion, and the following embodiments will be described by taking phosphorus diffusion as an example.

Example 1a

Taking phosphorus diffusion as an example:

(1) feeding the boat loaded with the silicon wafers into a furnace tube;

(2) vacuumizing and detecting leakage;

(3) after the temperature of the furnace tube is increased to 770 ℃, introducing oxygen and nitrogen, wherein the flow rate of the oxygen is 1L/min, the flow rate of the nitrogen is 3L/min, the pressure of the furnace tube is 160mbar, and the time is 5 min;

(4) keeping the temperature at 770 ℃, and carrying POCl with small nitrogen ₃ The source, mixed oxygen and big nitrogen are fed from the tail of the furnace, the flow rate of small nitrogen is 1.2L/min, the flow rate of oxygen is 0.8L/min, the flow rate of big nitrogen is 3L/min, the pressure of the furnace tube is 160mbar, and the time is 12 min;

in this embodiment, the

boat

1 or 2 corresponds to the first temperature zone, and the temperature of the first temperature zone is adjusted to 795 ℃. The No. 3 boat corresponds to a second temperature zone, and the temperature of the second temperature zone is adjusted to 780 ℃.

The first temperature zone and the second temperature zone are the positions of the thermal fields corresponding to the 1 st, 2 nd and 3 rd boats.

(5) Raising the temperature from 770 ℃ to 845 ℃ in a slope for 10 min; the oxygen flow is 1L/min, the nitrogen flow is 3L/min, and the furnace tube pressure is 160 mbar;

(6) keeping the temperature at 845 ℃ for 10min, supplementing nitrogen in the constant temperature process, wherein the nitrogen flow is 3L/min, and the furnace tube pressure is 160 mbar;

(7) cooling to 800 ℃, introducing nitrogen to return to normal pressure, and discharging.

Fig. 5 shows a schematic diagram of an air intake method adopted in this embodiment, where 1 denotes a tail flow equalizing plate, 2 denotes a furnace tube, 3 denotes a thermal field, 4 denotes a furnace opening heat insulating plate, 5 denotes a furnace door, 6 denotes a paddle, 7 denotes a tail pipe, 8 denotes an air intake pipe, and 9 denotes an air supply pipe.

Taking silicon wafers in 8 boats from a furnace mouth to a furnace tail in sequence, taking 5 wafers from each boat from top to bottom at equal intervals, testing the sheet resistance at 5 places in each boat, and calculating the range difference of 25 measurement points in the 5 wafers. The silicon wafer size 182mmx182mm, the comparative sheet resistance, range of the target sheet resistance 160 Ω/□ are shown in Table 1 below.

TABLE 1

Example 2a

On the basis of the embodiment 1a, the original uniform flow plate is removed, and a uniform flow barrel N is added at the tail of the furnace ₂ ，O ₂ ，POCl ₃ Allowing the gas to enter the furnace tube through the uniform flow barrel; the gas is uniformly scattered after entering the furnace tube, and the gas flow is prevented from directly impacting the silicon wafer. Specifically, the uniform flow barrel is placed in the furnace tube, and the distance between the uniform flow barrel and the end part of the gas inlet tube at the tail part of the furnace is 10-15 cm.

In this embodiment, the uniform flow barrel is 10cm away from the end of the gas inlet pipe at the tail of the furnace, the uniform flow barrel is in a barrel-shaped design as shown in fig. 1-2, one end of the barrel body 1a is open, the other end of the barrel body is provided with a closed surface 2a, and the closed surface 2a is provided with an opening 3 a. In this embodiment, when using, let gas earlier through the trompil 3a of closed surface, flow out through the staving again. In other embodiments, other configurations of the flow evening devices may be employed.

The remaining steps in this example are the same as in example 1 a.

In the same manner, the calculated sheet resistance difference is shown in table 2.

TABLE 2

Example 3a

On the basis of the embodiment 2a, an air supplement pipe is added, and the air supplement pipe is inserted from the furnace tail and extends to the furnace mouth. In this embodiment, a quartz air supply pipe is used, and one end of the air supply pipe close to the furnace mouth is closed while the other end is open for ventilation.

In this example, the No. 1 boat is arranged near the furnace opening heat shield, and the No. 2, 3, and 4 … 8 boats are arranged in this order toward the furnace tail.

3 holes are respectively formed in the positions corresponding to No. 1 boat along the length directions of 1/4, 1/2 and 3/4 of the furnace tube on the air supply pipe; 2 holes are respectively formed at 1/3 and 2/3 positions corresponding to the No. 2 boat along the length direction of the furnace tube; 1 hole is respectively arranged at 1/2 along the length direction of the furnace tube corresponding to the No. 3 boat; the aperture is 1.5 mm.

In this embodiment, the opening is a circular hole, and in other embodiments, the shape of the opening may be set to other shapes, which is not specifically limited by the present invention.

On the basis of the process of example 1a, the step (4) is modified as follows:

(4) constant temperature 770 deg.C, small nitrogen carrying POCl ₃ The source, mixed oxygen and big nitrogen are fed from the furnace tail, the flow rate of small nitrogen is 1.2L/min, the flow rate of oxygen is 0.8L/min, the flow rate of big nitrogen is 3L/min, the pressure of the furnace tube is 160mbar, the time is 12min, 0.95L/min nitrogen is introduced into the air supply tube, and the temperature of the No. 1, 2 and 3 boats corresponding to the first temperature zone and the second temperature zone is improved by 5 degrees compared with that of the embodiment 1.

In this embodiment, the nitrogen gas is introduced (i.e., the nitrogen gas compensation is turned on) under the condition of source introduction, and the nitrogen gas is closed in the rest of time, and the nitrogen gas introduction time is consistent with the source introduction time. In other embodiments, an inert gas, such as helium, is introduced into the fill tube.

The remaining steps in this example are the same as example 2 a.

In the same manner of taking the film, the measured sheet resistance is as the following table 3.

TABLE 3

The sheet resistance of example 3 was the least poor. Compared with the embodiment 1, in the embodiment 3, the uniform flow barrel is added at the tail part of the furnace, and the air supplement pipe is added. In example 3, the difference in sheet resistance between the first three boats was small, the uniformity between wafers (i.e., (maximum-minimum)/2-average value of the sheet resistance of the silicon wafers in the boat) was improved, and the uniformity between the whole wafers was also greatly improved, as compared to example 1.

According to the method, under the conditions that the silicon wafer size is 182mmx182mm and the target sheet resistance is 160 omega/□, the concentration of a doping source of a furnace mouth close to a pumping hole (the pumping hole is the air inlet of a tail pipe) is diluted and reduced by supplementing nitrogen, air flow is mixed and pushed upwards, the influence of the pumping hole on the position is reduced, the concentration difference is reduced, and therefore the extremely poor sheet resistance of the silicon wafer is reduced. The uniform flow barrel is added at the tail part of the furnace, and after the air flow is fully dispersed, the air flow flows into the small boats as much as possible, so that the extreme difference of the boats close to the tail of the furnace is greatly improved. On the premise of large-size silicon wafers, high sheet resistance and high-efficiency battery technology, the uniformity requirement of the sheet resistance of the silicon wafers is higher and higher, the problem of the conventional diffusion technology is gradually revealed, and the process quality needs to be improved in multiple ways.

The silicon chip near the air exhaust opening is provided with the air supplement part by increasing the silicon chip near the air exhaust opening (one end of the tail exhaust pipe in the furnace tube), so that the non-uniformity of the silicon chip square resistance near the air exhaust opening is solved, and the extreme difference of the square resistance is reduced. In a conventional mode, partial silicon wafers near the air exhaust opening need to be abandoned, and the loading capacity of a single silicon wafer is reduced to obtain the uniformity of the whole tube. According to the method and the device, the square resistance range of the silicon wafer close to the air suction opening can be directly improved, so that the uniformity of the silicon wafer reaches the qualified area, and the productivity is improved.

As shown in fig. 5, in the conventional air intake mode, the airflow at the silicon wafer position under the furnace mouth is larger due to the deviation of the airflow at the furnace mouth to the tail discharge mouth, and the density of the doping gas is generally larger, so that the gas concentration under the furnace mouth is large and the flow is large, thereby causing the square resistance of the silicon wafer under the furnace mouth to be smaller and the square resistance range of the silicon wafer to be larger. The conventional method is used for adjusting the pressure of the furnace tube, improving the air flow proportion and changing the temperature of the silicon wafer at the furnace opening to improve the sheet resistance abnormity of the silicon wafer at the furnace opening. Similar problems exist in the way of furnace mouth gas inlet and furnace tail gas exhaust. Such conventional adjustments can reduce the variance slightly, but have limited improvement to keep the silicon chips stable elsewhere. The number of wafers at the gas outlet is typically reduced to achieve uniformity across the tube of wafers.

This application increases a nitrogen gas pipeline in fire door department, fills nitrogen gas in the bottom, as shown in fig. 6, not only can dilute the high concentration dopant gas of here, can also upwards promote the misce bene with the air current of here, reduces the draft of tail calandria to here.

It should be apparent that the described embodiments are only a few embodiments of the present application, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

Claims

1. An air inlet structure is characterized by comprising a flow homogenizing device, wherein the flow homogenizing device adopts a barrel-shaped structure and comprises a barrel body, one end of the barrel body is opened, the other end of the barrel body is connected with a closed surface, and an opening is formed in the closed surface;

the gas inlet structure further comprises a gas supplementing pipe configured to be used for supplementing gas, wherein the gas is nitrogen or/and inert gas.

2. An air intake structure according to claim 1, wherein the flow equalizer is provided at a lower portion thereof with a support member, and the support member is fixedly connected to the tub.

3. An air intake structure according to claim 2, wherein the support member is cylindrical.

4. An air intake structure according to claim 2, wherein the support member is hollow internally.

5. An air intake structure according to claim 4, wherein the support member is open at one end.

6. An air intake structure according to claim 2, wherein the flow evening device further comprises a connecting member, the connecting member being connected to the support member.

7. An air intake structure according to claim 6, wherein the connector is located on the side of the opening of the barrel.

8. A gas inlet arrangement according to claim 1, wherein the gas supply duct is in the form of a plug, the gas supply duct being closed at one end and open at the other end for the introduction of gas, the gas supply duct being provided with a gas outlet.

9. A gas inlet structure according to claim 1, wherein the gas supply pipe is inserted into the furnace tube from the furnace tail and extends to the furnace mouth; the end of the air supply pipe close to the furnace mouth is closed, and the other end is opened.